The error message indicates that both devices (i.e., 192.168.11.3 and 192.168.11.4) have the same LLDP chassis ID.
The reason for the error is because LLDP (Link Layer Discovery Protocol) requires the chassis ID to be unique. The chassis ID is based on the system name.

To resolve the error, check the system name for both devices and verify that they are unique using the following steps.

Open the 'device' list by clicking on the 'Device' tab.

Verify that the names are unique.

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If the 'system Name' is not unique, use the following steps to change it.